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//
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// notice, this list of conditions and the following disclaimer.
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// in the documentation and/or other materials provided with the
// distribution.
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// this software without specific prior written permission.
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#ifndef BASE_NON_THREAD_SAFE_H__
#define BASE_NON_THREAD_SAFE_H__

#include "base/logging.h"

// A helper class used to help verify that methods of a class are
// called from the same thread.  One can inherit from this class and use
// CalledOnValidThread() to verify.
//
// This is intended to be used with classes that appear to be thread safe, but
// aren't.  For example, a service or a singleton like the preferences system.
//
// Example:
// class MyClass : public NonThreadSafe {
//  public:
//   void Foo() {
//     DCHECK(CalledOnValidThread());
//     ... (do stuff) ...
//   }
// }
//
// In Release mode, CalledOnValidThread will always return true.
//
#ifndef NDEBUG
class NonThreadSafe {
 public:
  NonThreadSafe();
  ~NonThreadSafe();

 protected:
  bool CalledOnValidThread() const;

 private:
  int32 valid_thread_id_;
};
#else
// Do nothing in release mode.
class NonThreadSafe {
 public:
  NonThreadSafe() {}
  ~NonThreadSafe() {}

 protected:
  bool CalledOnValidThread() const {
    return true;
  }
};
#endif  // NDEBUG

#endif  // BASE_NON_THREAD_SAFE_H__